Thread-rolling machine with rotatable rolling plates

ABSTRACT

A thread-rolling machine includes a vertical rotating shaft journalled on a machine base, and a thread-rolling unit. The thread-rolling unit includes a plurality of angularly equidistant rotatable rolling plates fixed on the rotating shaft, and a plurality of angularly equidistant fixed rolling plates fixed on the machine base and disposed around the rotatable rolling plates. During rotation of the rotating shaft, nail-shaped blanks are fed simultaneously onto the thread-rolling unit. Each of the blanks is rolled between a respective one of the rotatable rolling plates and a respective one of the fixed rolling plates, thereby forming a bolt.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a thread-rolling machine, and moreparticularly to a rotating type thread-rolling machine, which includes aplurality of rotatable rolling plates and a plurality of fixed rollingplates, between which a plurality of blanks can be processedsimultaneously.

[0003] 2. Description of the Related Art

[0004] Referring to FIGS. 1 and 2, a reciprocating type conventionalthread-rolling machine 1 is shown to include a machine base 11 avibrating unit 12, a channel member 13 that has a U-shapedcross-section, a flywheel 14, a linkage 15, a push plate 16, a drivingwheel 17, a link 18, a movable rolling plate 19, a mounting member 20and a fixed rolling plate 21. A plurality of headed nail-shaped blanks121 are fed from the vibrating unit 12 into the channel member 13 so asto move into a space between the mounting member 20 and the movablerolling plate 19. When the flywheel 14 is driven, the driving wheel 17rotates to reciprocate the movable rolling plate 19 along a guidingmember 110 that has an inverted U-shaped cross-section. Under suchconditions, the flywheel 14 activates the linkage 15 such that the pushplate 16 pushes the blanks 121 from the channel member 13 onto themovable rolling plate 19 one by one at a time interval. Subsequently,one of the blanks 121 is carried on and moves with the movable rollingplate 19 each time to press against the fixed rolling plate 21. Each ofthe movable rolling plate 19 and the fixed rolling plate 21 is formedwith a plurality of inclined parallel ribs (not shown) that can pressinto the blanks 121, thereby forming helical grooves (not shown) on theblanks 121.

[0005] Some of the disadvantages of the aforesaid conventionalthread-rolling machine 1 are as follows:

[0006] (1) The production rate of the machine 1 is severely limited:

[0007] During reciprocal movement of the movable rolling plate 19, theblanks 121 are processed only when the former moves from the positionshown by the solid lines in FIG. 2 to that shown by the phantom lines inFIG. 2. That is to say, no thread-rolling action is performed duringmovement of the movable rolling plate 19 from the position shown by thephantom lines in FIG. 2 to that shown by the solid lines in FIG. 2,thereby resulting in a low production rate of the machine 1.

[0008] (2) There is a need for a relatively high power during the threadrolling operation:

[0009] In order to form bolts from the blanks 121, it is necessary todrive the flywheel 14, the linkage 15, the push plate 16, the drivingwheel 17, the link 18 and the movable rolling plate 19, therebyresulting in a power-consuming process.

[0010] (3) The structure of the machine 1 is relatively complex:

[0011] The machine 1 consists of numerous elements, thereby resulting ina relatively complex structure, which will increase the manufacturingcosts.

[0012] (4) It is dangerous to check if the blanks 121 are processedwell:

[0013] In the art, a person responsible for quality control is requiredto check the quality of the bolt products during the thread rollingoperation, and usually receives the bolts dropping from the movablerolling plate 19 and the fixed rolling plate 21 with one hand that wearsa glove. The glove may come onto contact with and be drawn by themovable rolling plate 19 to move, thereby hurting the hand of theperson.

[0014] (5) The height of the movable rolling plate 19 is also limited:

[0015] The machine 1 can process the blank 121 to form a bolt with athreaded section, which has a length that is not longer than the heightof the movable rolling plate 19. However, the height of the movablerolling plate 19 is limited by the size of the guiding member 110,thereby reducing the applicable range of the machine 1.

[0016] (6) The noise incurred during the thread rolling operation isrelatively large:

[0017] The moving parts of the machines 1 are numerous, therebyresulting in a comparatively noisy thread rolling operation.

SUMMARY OF THE INVENTION

[0018] An object of this invention is to provide a highly efficientrotating type thread-rolling machine, which has a simple structure,thereby resulting in a power-saving thread rolling operation.

[0019] Another object of this invention is to provide a thread-rollingmachine with a plurality of bolt-guiding plates, which can preventinjury to one hand of a person responsible for quality control thataccepts the bolt products dropping from the rolling plates when he orshe checks the quality of the products during the thread rollingoperation of the machine.

[0020] Still another object of this invention is to provide a rotatingtype thread-rolling machine with replaceable rotatable rolling plates,which have a height that can be selected optionally according to thedesired length of the bolt products.

[0021] Yet another object of this invention is to provide a rotatingtype thread-rolling machine, which can reduce noise incurred during thethread rolling operation of the machine.

[0022] According to this invention, a thread-rolling machine includes amachine base, a vertical rotating shaft journalled on the machine base,a thread-rolling unit and a plurality of feeding units. Thethread-rolling unit includes a plurality of angularly equidistantrotatable rolling plates disposed fixedly on the rotating shaft, and aplurality of angularly equidistant fixed rolling plates disposed fixedlyon the machine base and disposed around the rotatable rolling plates.Each of the rotatable rolling plates and the fixed rolling plates isformed with a cutting surface that has a rolling-starting side and arolling-ending side. Each of the feeding units is adapted to feed a rowof headed nail-shaped blanks toward a standby position during rotationof the rotating shaft relative to the machine base. Each of the standbypositions of the blanks is adjacent to the rolling-starting sides of thecutting surfaces of a respective one of the rotatable rolling plates anda respective one of the fixed rolling plates such that the blanks fedfrom a respective one of the feeding units can reach a respective one ofthe standby positions one by one at a time interval so as to permitmovement of each of the blanks onto the rotatable rolling plates andsubsequent rolling of the blanks between the rotatable rolling platesand the fixed rolling plates, thereby forming simultaneously a pluralityof bolts during each thread rolling operation of the thread-rollingunit.

[0023] Preferably, the machine further includes a plurality of stopplates, which are fixed respectively to the fixed rolling plates andwhich are disposed respectively adjacent to the rolling-ending sides ofthe cutting surfaces of the fixed rolling plates so as to be adapted tocontact the bolts when the bolts separate from the rolling-ending sidesof the cutting surfaces of the fixed rolling plates, thereby permittingdropping of the bolts from the stop plates. A plurality of containersare disposed below the stop plates, respectively, and have open upperends. A plurality of bolt-guiding plates have upper ends that aredisposed proximately below the stop plates, respectively, and lower endsthat are disposed proximately above the upper ends of the containers, soas to be adapted to permit movement of the bolts on the bolt-guidingplates, thereby guiding the bolts from the stop plates into the upperends of the containers. Because the bolt-guiding plates are adapted tobe located between the rotating shaft and the bolts when the bolts moveon the bolt-guiding plates, when a person responsible for qualitycontrol accepts one of the bolts dropping from the rotatable rollingplate and the fixed rolling plate with one hand during the threadrolling operation of the machine, the bolt-guiding plates can preventthe hand of the person from coming into contact with the rotating shaft,thereby avoiding injury to the hand.

[0024] Because no guiding means is provided to guide the rotatablerolling plates, the height of the latter is not limited, therebypermitting a wider range of height change.

[0025] Furthermore, because there is no need for a high power and alinkage for driving the rotatable rolling plates, noise incurred duringthe thread rolling operation is reduced significantly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] These and other features and advantages of this invention willbecome apparent in the following detailed description of a preferredembodiment of this inventions with reference to the accompanyingdrawings, in which:

[0027]FIG. 1 is a fragmentary perspective view of a reciprocating typeconventional thread-rolling machine;

[0028]FIG. 2 is a schematic top view of the conventional thread-rollingmachine, illustrating how a movable rolling plate is driven in order toform a bolt from a blank that is shaped as a headed nail;

[0029]FIG. 3 is a schematic side view of the preferred embodiment of athread-rolling machine according to this invention;

[0030]FIG. 3A is a schematic view illustrating cutting surfaces of arotatable rolling plate and a fixed rolling plate of the preferredembodiment;

[0031]FIG. 4 is a schematic top view of the preferred embodiment,illustrating how a plurality of blanks are fed in rows;

[0032]FIG. 5 is a schematic top view of the preferred embodiment,illustrating how four bolt products are moved onto four stop plates;

[0033]FIG. 6 is a schematic view of a release device of the preferredembodiment, when a blocking plate is disposed at an extended position;and

[0034]FIG. 7 is a schematic view of the release device of the preferredembodiment, when the blocking plate is disposed at a retracted position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0035] Referring to FIGS. 3, 3A and 4, the preferred embodiment of arotating type thread-rolling machine 5 according to this invention isshown to include a machine base 51, a vertical rotating shaft 52, athread-rolling unit consisting of four angularly equidistant rotatablerolling plates 531 and four angularly equidistant fixed rolling plates532, a surrounding plate unit 54, and four angularly equidistant feedingunits 55.

[0036] The rotating shaft 52 is journalled and rotates counterclockwiseon the machine base 51. Each of the rotatable rolling plates 531 isfixed to an annular surface of the rotating shaft 52, and is formed witha cutting surface (531A) that has a rolling-starting side (531B) and arolling-ending side (531C).

[0037] The surrounding plate unit 54 is fixed on the machine base 51, islocated around the rotating shaft 52, and consists of four curved plates541, which are arranged in a circle. Each adjacent pair of the plates541 defines a space 542 therebetween. The fixed rolling plates 532 arefixed respectively to the inner side surfaces of the plates 541. Each ofthe fixed rolling plates 532 is formed with a cutting surface (532A)that has a rolling-starting side (532B) and a rolling-ending side(532C). Each of the rotatable rolling plates 531 and the fixed rollingplates 532 is formed with a plurality of inclined parallel ribs (R) (seeFIG. 3A) in a known manner. Each of the fixed rolling plates 532 isprovided with a V-shaped stop plate 533, which is mounted fixedlythereto so as to define a bolt-trapping space 534 therebetween.

[0038] Each of the feeding units 55 includes a funnel-shaped vibratingunit 551 for receiving and feeding a row of blanks 56 that are shaped asheaded nails, and a channel member 552, which extends through arespective one of the spaces 542 in the surrounding plate unit 54. Eachof the channel members 552 has a U-shaped cross-section, an inner end(552A) that is disposed adjacent to the rolling-starting sides (531B,532B) of the cutting surfaces (531A, 532A) of a respective one of therotatable rolling plates 531 and a respective one of the fixed rollingplates 532, an outer end (552B) that is attached to a respective one ofthe vibrating units 551, and two aligned walls 553 that define a slideslot 554 therebetween so as to permit sliding movement of the heads 561of the blanks 56 on the top surf aces of the walls 553. The walls 553have a height that reduces gradually from the outer ends (552B) to theinner ends (552A). As such, when the vibrating units 551 vibrate, theblanks 56 can slide from the vibrating units 551 toward thethread-rolling unit along the channel members 552. The inner end (552A)of each of the channel members 552 is provided with an electromagneticrelease device 555, which includes an inverted U-shaped mounting member556 that is disposed fixedly on the walls 553, and a movable blockingplate 557 (see FIG. 6) that is movable between an extended positionshown in FIG. 6, where the blocking plate 557 contacts and prevents theleading one of the blanks 56 from moving on the inner end (552A) of thechannel member 552, and a retracted position shown in FIG. 7, where theleading one of the blanks 56 can move from the channel member 552 to astandby position, where the head 561 of the leading blank 56 issupported on a top surface of one rotatable rolling plate 531 so as topermit the leading blank 56 to move into a space between the rotatablerolling plate 531 and one fixed rolling plate 532. The release devices555 cooperates with the rotating shaft 52 and the rotatable rollingplates 531 under a timing control so that each releasing action of eachrelease device 555 can release only one of the blanks 56. In addition,under the timing control, the blanks 56 always move onto therolling-starting sides (531B) of the cutting surfaces (531A) of therotatable rolling plates 531, and will not move into spaces between therotatable rolling plates 531.

[0039] Subsequently, the blanks 56 roll and rotate clockwise between therotatable rolling plates 531 and the fixed rolling plates 532, and moveon the cutting surfaces (531A, 532A) from the rolling-starting sides(531B, 532B) to the rolling-ending sides (531C, 532C), thereby formingfour bolts 561′ (see FIG. 5) simultaneously during each thread rollingoperation of the thread-rolling unit, which consists of the rotatablerolling plates 531 and the fixed rolling plates 532. As such, thethread-rolling unit can form sixteen bolts 561′ during each revolutionof the rotating shaft 52. The heads 561 of the blanks 56 are supportedon the top surfaces of the rotatable rolling plates 531 and the fixedrolling plates 532 during rolling of the blanks 56 between the rotatablerolling plates 531 and the fixed rolling plates 532. Referring to FIG.5, as soon as the bolts 561′ separate from the rolling-ending sides(532C) of the cutting surfaces (532A) of the fixed rolling plates 532,they contact the stop plates 533, thereby dropping from thebolt-trapping spaces 534.

[0040] Referring again to FIG. 3, four curved bolt-guiding plates 512(only two are shown) are disposed fixedly on the machine base 51, andare located around the rotating shaft 52. Each bolt-guiding plate 512has an upper end that is disposed proximately below the correspondingstop plate 533, and a lower end that is disposed proximately above anopen upper end 514 of a container 513, so as to permit movement of thebolts 561′ on the bolt-guiding plate 512, thereby guiding the bolts 561′from the stop plates 533 into the upper ends 514 of the containers 513.

[0041] When a person responsible for quality control accepts the bolts561′ from the bolt-guiding plates 512 with one hand, because thebolt-guiding plates 512 are located between the rotating shaft 52 andthe bolts 561′, they can prevent the hand from coming into contact withthe rotating shaft 52, thereby preventing injury to the hand.

[0042] The rotatable rolling plates 531 may be mounted removably on themachine base 51, thereby permitting replacement of the former based onthe desired length of the threaded portions of the bolt products 561′.

[0043] Furthermore, the rotating type thread-rolling machine of thisinvention has the advantages of simple structure, power-savingoperation, and reduced noise during the thread rolling operation.

[0044] With this invention thus explained, it is apparent that numerousmodifications and variations can be made without departing from thescope and spirit of this invention. It is therefore intended that thisinvention be limited only as indicated by the appended claims.

I claim:
 1. A rotating type thread-rolling machine comprising: a machinebase; a vertical rotating shaft journalled on said machine base; athread-rolling unit including a plurality of angularly equidistantrotatable rolling plates disposed fixedly on said rotating shaft, eachof said rotatable rolling plates being formed with a cutting surfacethat has a rolling-starting side and a rolling-ending side, and aplurality of angularly equidistant fixed rolling plates disposed fixedlyon said machine base and disposed around said rotatable rolling plates,each of said fixed rolling plates being formed with a cutting surfacethat has a rolling-starting side and a rolling-ending side; and aplurality of angularly equidistant feeding units disposed on saidmachine base, each of said feeding units being adapted to feed a row ofheaded nail-shaped blanks toward a standby position during rotation ofsaid rotating shaft relative to said machine base, each of the standbypositions of the blanks being adjacent to said rolling-starting sides ofsaid cutting surfaces of a respective one of said rotatable rollingplates and a respective one of said fixed rolling plates such that theblanks fed from a respective one of said feeding units can reach arespective one of the standby positions one by one at a time interval soas to permit movement of each of the blanks onto said rotatable rollingplates and subsequent rolling of the blanks between said rotatablerolling plates and said fixed rolling plates, thereby formingsimultaneously a plurality of bolts during each thread rolling operationof said thread-rolling unit.
 2. The thread-rolling machine as claimed inclaim 1, further comprising: a plurality of stop plates fixedrespectively to said fixed rolling plates and disposed respectivelyadjacent to said rolling-ending sides of said cutting surfaces of saidfixed rolling plates so as to be adapted to contact the bolts when thebolts separate from said rolling-ending sides of said cutting surfacesof said fixed rolling plates, thereby permitting dropping of the boltsfrom said stop plates; a plurality of containers disposed below saidstop plates, respectively, and having open upper ends; and a pluralityof bolt-guiding plates having upper ends that are disposed proximatelybelow said stop plates, respectively, and lower ends that are disposedproximately above said upper ends of said containers, so as to beadapted to permit movement of the bolts on said bolt-guiding plates,thereby guiding the bolts from said stop plates into said upper ends ofsaid containers, said bolt-guiding plates being adapted to be locatedbetween said rotating shaft and the bolts when the bolts move on saidbolt-guiding plates.
 3. The thread-rolling machine as claimed in claim2, wherein said stop plates are generally V-shaped so as to define abolt-trapping space between a respective one of said stop plates and arespective one of said fixed rolling plates, thereby permitting movementof the bolts into said spaces when the bolts separate from saidrolling-ending sides of said cutting surfaces of said fixed rollingplates.